/*

  * Copyright 2009 Ange Optimization ApS

  *

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  *     http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package eu.simuline.octave.io.impl;

 import java.io.BufferedReader;

 import eu.simuline.octave.exception.OctaveParseException;

 import eu.simuline.octave.io.OctaveIO;

 import eu.simuline.octave.io.spi.OctaveDataReader;

 import eu.simuline.octave.type.OctaveComplex;

 import eu.simuline.octave.util.StringUtil;

 /**

  * Reader for the octave type "complex matrix" 

  * reading an {@link OctaveComplex} from a {@link BufferedReader}. 

  * Note that the entries are of type "complex scalar". 

  *

  * Format is:

  *

  * <pre>

  * # type: complex matrix

  * # rows: 2

  * # columns: 2

  *  (1.1,0) (0,1.1)

  *  (2.2,0) (0,2.2)

  * </pre>

  */

 // **** seems as if this is not general enough. 

 // **** should be subclass of AbstractGenericReader? 

 public final class ComplexMatrixReader extends OctaveDataReader {

     private static final String COLUMNS = "# columns: ";

     private static final String ROWS    = "# rows: ";

     @Override

     public String octaveType() {

         return "complex matrix";

     }

     @Override

     public OctaveComplex read(final BufferedReader reader) {

         final int rows = parseRows(reader);

         final int columns = parseColumns(reader);

         final OctaveComplex complex = new OctaveComplex(rows, columns);

         for (int r = 1; r <= rows; ++r) {

             final String line = OctaveIO.readerReadLine(reader);

             final String[] split = line.split(" ");

             if (split.length != columns + 1) {

                 throw new OctaveParseException

                     ("Error in complex matrix-format: '" + line + "'");

             }

             for (int c = 1; c < split.length; c++) {

                 final int commaIndex = split[c].indexOf(',');

                 final double real = StringUtil

                     .parseDouble(split[c].substring(1, commaIndex));

                 final double imag = StringUtil

                     .parseDouble(split[c].substring(commaIndex + 1,

                                                     split[c].length() - 1));

                 complex.setReal(real, r, c);

                 complex.setImag(imag, r, c);

             }

         }

         return complex;

     }

     /**

      * @param reader

      * @return

      *   the number of rows

      */

     public int parseRows(final BufferedReader reader) {

         final String line = OctaveIO.readerReadLine(reader);

         if (!line.startsWith(ROWS)) {

             throw new OctaveParseException

                 ("Expected <" + ROWS + "> got <" + line + ">");

         }

         return Integer.parseInt(line.substring(ROWS.length()));

     }

     /**

      * @param reader

      * @return

      *    the number of columns

      */

     public int parseColumns(final BufferedReader reader) {

         final String line = OctaveIO.readerReadLine(reader);

         if (!line.startsWith(COLUMNS)) {

             throw new OctaveParseException

                 ("Expected <" + COLUMNS + "> got <" + line + ">");

         }

         return Integer.parseInt(line.substring(COLUMNS.length()));

     }

 }